Rotatable fire sprinkler fitting with elongated gasket

ABSTRACT

A pipe fitting, useable in the installation of a sprinkler head, includes (a) a body having an open upstream end and an open downstream end, the downstream end having internal threads capable of accepting a threaded male fitting, the body defining an gasket retention area located upstream of the internal threads; and (b) an gasket disposed within the gasket retention area. The gasket retention area and the gasket are chosen so that a threaded male fitting threadedly disposed within the downstream end of the body can be rotated within the downstream end of the body 360° while remaining liquid tight for pressures in excess of 300 psig.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/536,654, filed on Aug. 6, 2009, now U.S. Pat. No. 8,297,663, entitledROTATABLE FIRE SPRINKLER FITTING WITH ELONGATED GASKET, the entirety ofwhich is incorporated herein by reference, which was a continuation ofU.S. patent application Ser. No. 12/418,745, filed on Apr. 6, 2009, nowabandoned, entitled ROTATABLE FIRE SPRINKLER FITTING WITH ELONGATEDGASKET, the entirety of which is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to pipe fittings and, morespecifically, to pipe fittings used to install fire sprinkler systems.

BACKGROUND OF THE INVENTION

Fire sprinkler systems are increasingly recognized as necessary safetyfeatures in the construction of new buildings and in the upgrading ofexisting buildings. There is a problem, however, in the installation offire sprinkler systems.

Many styles of fire sprinkler heads have built-in deflectors thatrequire rotational orientation of the sprinkler head to correctlyposition the deflector to produce the desired spray pattern when thehead operates. All prior art fire sprinkler heads are attached to thepiping mains by tapered pipe threads designed to produce a water tightseal using the interference of the tapered threads, plus either or bothof a thread tape or thread paste. Thus, it can be appreciated thatproper orientation of prior art sprinkler heads can usually only beaccomplished by under-tightening the sprinkler heads or over-tighteningthe sprinkler heads. Overtightening of the tapered pipe threads producesinterference between the mating threads, resulting in distortion of themating parts. Undertightening over the tapered pipe threads can producedleaks.

Accordingly, there is a need for a fire sprinkler fitting which avoidsthe aforementioned in the prior art.

SUMMARY

The invention satisfies this need. The invention is a pipe fittinguseable in the installation of a sprinkler head. The pipe fittingcomprises (a) a body having an open upstream end and an open downstreamend, the downstream end having internal threads capable of accepting athreaded male fitting, the body defining an gasket retention arealocated upstream of the internal threads; and (b) an gasket disposedwithin the gasket retention area. In the invention, the gasket retentionarea and the gasket are chosen so that a threaded male fittingthreadedly disposed within the downstream end of the body can be rotatedwithin the downstream end of the body 360° while remaining liquid tightfor pressures in excess of 300 psig.

DRAWINGS

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription, appended claims and accompanying drawings where:

FIG. 1 is an exploded perspective view of a fire sprinkler fittinghaving features of the invention;

FIG. 2 is a plan view of a gasket useable in the invention;

FIG. 3 is a cross-sectional view of the gasket illustrated in FIG. 2;

FIG. 4 is an exploded perspective view illustrating the installation ofa fire sprinkler into the fitting illustrated in FIG. 1;

FIG. 5 illustrates the combination of a fire sprinkler and the fittingillustrated in FIG. 1 showing the additional tightening of the firesprinkler within the fitting;

FIG. 6 illustrates the combination illustrated in FIG. 5, but showingthe fire sprinkler further rotated within the fitting for proper finalalignment;

FIG. 7 is a partial cross-section of a fire sprinkler within the fittingillustrated in FIG. 1 showing the fire sprinkler initially threaded intothe fitting;

FIG. 8 is a partial cross-section of the combination illustrated in FIG.7 taken along line 5-5, but showing the fire sprinkler fluid tightwithin the gasket within the fitting; and

FIG. 9 is a partial cross-section of the fire sprinkler and fittingcombination illustrated in FIG. 7 taken along line 6-6, but showing thefire sprinkler further rotated within the fitting, while remaining fluidtight against the gasket.

DETAILED DESCRIPTION

The following discussion describes in detail one embodiment of theinvention and several variations of that embodiment. This discussionshould not be construed, however, as limiting the invention to thoseparticular embodiments. Practitioners skilled in the art will recognizenumerous other embodiments as well.

The invention is a pipe fitting 10 which can be advantageously used inthe installation of a fire sprinkler head 12. The pipe fitting 10 of theinvention comprises a body 14 and an elongated gasket 16.

FIGS. 1 and 4-6 are perspective views of the body 14 in one embodimentof the invention. FIGS. 7-9 illustrate the body 14 in cross-section. Thebody 14 is typically made from cast iron, steel, copper or brass. Othermaterials can also be used, such as cross-linked polyethylene havingmetallic thread inserts.

The body 14 has an open upstream end 18 and an open downstream end 20.The downstream end 20 has internal threads 22 capable of accepting athreaded male fitting 24, such as the threaded male fitting 24 of thefire sprinkler head 12. Typically, such internal threads 22 are a ½−14NPT conforming to ASTM standard F1498, with the exception that the pitchdiameter is at the end to oversize. Tolerance for fit with a threadedplug gauge is +/−1½ turns these threads are made to approximately 2turns.

The body 14 defines a gasket retention area 26 located upstream of theinternal threads 22. The gasket retention area 26 is sized anddimensioned to accept and retain the gasket 16 both when the gasket 16is non-compressed and when the gasket 16 is fully compressed. The gasketretention area 26 is thus sized and dimensioned such that the gasket 16is never allowed to escape from the gasket retention area 26 into thethroat of the body 14.

The gasket 16 is disposed within the gasket retention area 26. Both thegasket 16 and the gasket retention area 26 are chosen so that a threadedmale fitting 24 threadedly disposed within the downstream end 20 of thebody 14 can be rotated within the downstream end 20 of the body 14 360°(one complete rotation) while remaining continuously fluid tight forpressures in excess for 300 psig, preferably in excess of 600 psig, morepreferably in excess of 850 psig and most preferably in excess of 875psig.

Typically, the gasket 16 is made from an elastomeric material. Manyknown elastomeric materials can be used in the gasket 16 such as EPDM,neoprene, silicone, buna-N, Hypalon, polyurethane, Santoprene, vinyl andViton.

As best illustrated in FIGS. 2 and 3, the gasket 16 has a non-roundcross-section with a longitudinal axis and a transverse axis. The lengthl₁ of the gasket cross-section, measured along the longitudinal axis, istypically between about 0.25 inches and about 0.3 inches for a gasket 16having an internal diameter between about 0.5 inches and about 0.7inches. The cross-section of the gasket 16 also has a width l₂, measuredalong the length of the traverse axis. Typically, l₂ is between about0.13 inches and about 0.15 inches for a gasket 16 having an internaldiameter between about 0.5 inches and about 0.7 inches.

In one typical embodiment, the gasket 16 has an inside diameter of about0.61 inches, a length l₁ of about 0.27 inches and a width l₂ of about0.139 inches.

It is typical in all embodiments that the ratio l₂/l₁ is typicallybetween about 0.4 and about 0.6.

In operation, the gasket 16 is disposed within the gasket retention area26 of the body 14 as illustrated, for example, in FIG. 7. Next, a firesprinkler head 12 can be disposed within the downstream end 20 of thebody 14. FIGS. 4 and 7 illustrate the initial sequence of threadilydisposing the fire sprinkler head 12 into the downstream end 20 of thebody 14.

Next, the fire sprinkler head 12 is threaded further into the body 14until the upstream end 18 of the fire sprinkler head 12 contacts thegasket 16 and sufficiently presses against the gasket 16 to effect aliquid tight seal with the gasket 16.

Lastly, the sprinkler head is rotated for up to 360° until it is inproper orientation. During this rotation, the sprinkler head 12 and thegasket 16 maintain a liquid tight seal. As noted above, this liquidtight seal can preferably withstand in excess of 300 psig, morepreferably in excess of 600 psig, still more preferably in excess of 850psig and most preferably in excess of 875 psig.

The invention thus provides the installer of fire sprinklers an easy,economical and quick way to install and properly align fire sprinklers.

Having thus described the invention, it should be apparent that numerousstructural modifications and adaptations may be resorted to withoutdeparting from the scope and fair meaning of the instant invention asset forth hereinabove and as described hereinbelow by the claims.

What is claimed is:
 1. A method for installing a fire sprinkler headconnected to a water supply line in a desired orientation, the watersupply line having an open pipe end and the fire sprinkler head having athreaded upstream end with a fitting end edge, the method comprising thesteps of: (a) providing a pipe fitting having: (i) a body having acircular cross-section, a longitudinal axis, side walls, an openupstream end and an open downstream end, the open downstream end beingsized and dimensioned to axially accept and retain an open pipe end, thedownstream end having internal threads capable of accepting a malefitting having external threads which terminate at a fitting end edge,the body defining a gasket retention area located upstream of theinternal threads; and (ii) an elongated gasket disposed within thegasket retention area, the elongated gasket having a pair of opposedlong sides and a pair of opposed short sides, the gasket retention areacomprising a circumferential notch defined in the side walls of the bodyand a flat gasket retention area base disposed in a plane perpendicularto the longitudinal axis of the body; wherein the gasket retention areaand the gasket are chosen so that said male fitting, when threadedlydisposed within the upstream end of the body, is capable of contacting ashort side of the gasket with the fitting end edge so as to laterallydistort the gasket, such that the threaded male fitting can be rotatedwithin the downstream end of the body 360° while remaining liquid tightfor pressures in excess of 300 psig; (b) attaching the body of the pipefitting to the water supply line by attaching the upstream end of thebody in fluid tight communication to the open pipe end of the watersupply line; (c) threading the upstream end of the fire sprinkler headinto the downstream end of the pipe fitting until the fitting end edgecontacts the gasket and sufficiently presses against the gasket toeffect a liquid tight seal with the gasket; and (d) further threadingthe upstream end of the fire sprinkler head into the downstream end ofthe pipe fitting up to 360° until the fire sprinkler head is disposed inthe desired orientation.
 2. The method of claim 1 wherein the body ismade from a material chosen from the group of materials consisting ofcast iron, steel, copper, brass and plastic material.
 3. The method ofclaim 1 wherein the body is made from a plastic material and wherein thegasket retention area and the gasket are chosen so that said malefitting, when threadedly disposed within the upstream end of the body,is capable of contacting a short side of the gasket with the fitting endedge so as to laterally distort the gasket, such that the threaded malefitting can be rotated within the downstream end of the body 360° whileremaining liquid tight for pressures in excess of 300 psig.
 4. Themethod of claim 1 wherein the gasket is made from an elastomericmaterial.
 5. The method of claim 1 wherein the gasket is made from anelastomeric material chosen from the group of elastomeric materialsconsisting of EPDM, neoprene, silicone, buna-N, Hypalon, polyurethane,Santoprene, vinyl and Viton.
 6. The method fitting of claim 1 whereinthe gasket is made from EPDM.
 7. The method of claim 1 wherein thegasket has a non-round cross-section having a longitudinal axis and atraverse axis, the length l₁ of the gasket cross-section measured alongthe longitudinal axis being between about 0.25 inches and 0.3 inches. 8.The method of claim 7 wherein the cross-section of the gasket has awidth l₂ measured along the length of the transverse axis which isbetween about 0.13 inches and 0.15 inches.
 9. The method of claim 8wherein the ratio of l₂/l₁ is between about 0.4 and about 0.6.
 10. Themethod of claim 1 wherein the gasket has an internal diameter betweenabout 0.5 inches and about 0.7 inches.
 11. The method of claim 1 whereinthe gasket retention area and the gasket are chosen so that a threadedmale fitting threadedly disposed within the downstream end of the bodycan be rotated within the downstream end of the body 360° whileremaining fluid tight for pressures in excess of 600 psig.
 12. Themethod of claim 1 wherein the gasket retention area and the gasket arechosen so that a threaded male fitting threadedly disposed within thedownstream end of the body can be rotated within the downstream end ofthe body 360° while remaining liquid tight for pressures in excess of850 psig.
 13. The method of claim 1 wherein a fire sprinkler is retainedwithin the downstream end of the body.